1. Field of the Invention
The present invention relates generally to the fields of imaging, thermotherapy, and cryotherapy. More specifically, the present invention relates to a method and system utilizing optoacoustic imaging to monitor, in real time, tissue properties during therapeutic or surgical treatment.
2. Description of the Related Art
Various types of therapeutic agents (radiation, heating, cooling, drugs, surgical tools) are being used for treatment. It is necessary to monitor tissue physical properties during treatment to provide selective damage to diseased tissues. This will result in better outcome of any treatment procedure. It is highly desirable to develop an imaging technique which will be capable of monitoring tissue physical parameters in real time during treatment. Such an imaging technique will provide feed-back information which will be used to optimize treatment procedure. All conventional imaging techniques have limitations such as low contrast (ultrasound and X-ray imaging), high cost (MRI, PET), poor resolution (PET). Some of them are not capable of providing imaging information in real time. Due to these limitations, these conventional techniques are not being widely applied for monitoring tissue physical properties in real time during treatment.
It has been demonstrated that thermally treated tissues possess optical properties that are significantly different from normal untreated tissues. For example, the optical properties of coagulated and normal tissues are different. It was also demonstrated that different regimes of coagulation may yield different end values of tissue optical properties. A hemorrhage ring was observed at the boundary between coagulated and normal tissue in vivo.
The prior art is deficient in the lack of effective means of monitoring of tissue parameters in real time during therapeutic or surgical treatment. The present invention fulfills this long-standing need and desire in the art.